Current rectifier



July 14, 1931. s. sTRAUss CURRENT RECTIFIER Filed June 26, 1929 PatentedJuly 14, 1931 UNITED STATES SIEGMUND sTRAUss, or VIENNA, AUSTRIA CURRENTRECTIFIER Application filed June 2G, 1929, Serial No. 373,877, and inAustria May 19, 1927.

The invention relates to a current rectifierof the kind employed inconnection with electric measuring apparatus and for other purposes,especially where condensers are to be u charged from a supply andconstant Voltage isrequired in spite of any fluctuation of the voltageof this supply. A current rectifier of the kind to be described in thefollowing is adapted for feeding a condenser forming part of themeasuring apparatus, which is for instance repeatedly charged from thesupply and is discharged through an ionic chamber or other highresistance, the value of which is to be measured. The frequency of thecondenser discharges within a certain time depends on the resistance tobe measured and on the voltage up to which the condenser is charged. Forexact measurement therefore constant voltage must be applied to thecondenser by the repeated charges, because otherwise no correct resultwould be obtained if the condenser voltage would be affected by everychange of the supply voltage.

According to the invention a constant voltage is obtained by deriving itfrom the terminals of a condenser' forming part of the rectifyingapparatus charged continuously by means of a thermionie or reetifyingvalve and by discharging the condenser at the same time through anotherthermionic valve, whereby in the arrangement according to the inventioninfluences of varying supply voltage are eliminated in a manner, whichwill be more fully described later and exact measurement will besecured.

The arrangement according to the invention may be as Well employed forother than measuring purposes as for instance for high voltagerectifying in connection with apparatus for Roentgen rays, cable testingsets and the like, wherein a constant value of continuous voltage is tobe maintained unaffected by any fluctuation of the supply voltage.

The object of the invention is shown in the accompanying drawings,wherein Fig. l shows a connection of a measuring apparatus according tothe invention,

Fig. 2 shows a similar but modified arrangement, vvherein the valveemployed is connected in a somewhat different manner.

Fig. 3 shows another arrangement, wherein constant voltage isobta'ined.

Referring vto Fig. 1 A and B are thermionic valves with heated filamentsF and F inversely connected in series with a condenser f.

Kto a source Q, of alternating'current, the derived voltage of which is'tobe held constant, that is one terminal N of the source of alternatingcurrent is connected to the plate P of valve A and at the same time tothe heating filament F of valve B and vice versa, the terminal N withthe plate 'P of valve B and the filament F 'of valve A. As is shown byFig. l the filaments F and F are heated by means of suitabletransformersT andT and adjustable resistances R and R from the sourceand the filament F of valve A is preferably heated to a somewhat higherdegree so that lthe electrons are emitted in accordance with the. actualvoltageapplied to the plate P, whereas the valve B, its filament F beingsubjected to a weaker heating, is working below saturation so that thecurrent of the plate P essentially depends on the heating effect.

If for 'instance the supply voltage increases the emission in valve Alikewise increases. In valve B, however, it increases to a much higherdegree. The charge of the condenser K thereby is carried away morerapidly andby adjusting the heating effect a practically constantvoltage on the condenser K may be obtained in an easy way. The arrangement of Fig. l beingc'ompletely symmetrical it is possible toimpart the inverse polarity to the condenser by varying the adjustableresistances R and R of the heating circuits.

Fig. 2 shows a similar connection in which the condenser K is connectedbetween the filament F and the plate P of' the valvie B f valves by wayof two condensers in series, one 1 of which is of extremely highinsulation and by deriving rectified current from the terminals of thecondenser, whe-h is insulated as usual, its voltage being affected bythe fluc- 5 tuations of the voltage of the main supply,

whereas from the other condenser with eX- tremely high insulation, a.small amount of constant current is supplied under nearly constantvoltage, unaffected by fluctuations.

This modification is shown by Fig. 3.

A transformer T is connected to the supply mains having a primarywinding U and four secondary circuits V, V and W, W two of them V, Vserving for heating the filaments of therectifying valves C, D and thetwo other windings WV, lV for' supplying alternating current which isconverted into continuous current. A continuous current is derivedeither from the terminals L, O of the condenser K, or from the terminalsO, Z of the condenser K2. The plates of the valves are connected to aneutral O and to one armature of either of the condensers K1 and K2.According to the invention the condenser K2 is made with extremely highinsulation,

whereas the condenser K1 is built up as usual.

Then if the current supplied from the condenser K2 is negligible thevoltage on co-ndenser K2 remains unaffected by any variation of thesupply voltage.

What I claim is 1. A current rectifier adapted to be connected withmeasuring apparatus for high resistances and ionic currents in which acondenser is employed repeatedly charged up to a constant voltage, saidrectifier comprising a condenser charged by way of a rectifying valvefrom a supply of current, another thermionie valve connected as adischarge path 40 by which part of the condenser charge is carried awayin dependence ofthe actual voltage value of the supply, this dependanceresultin g from heating the iilament of the thermionic valve from thesupply.

2. A current rectifier according to claim l, wherein the valves arearranged symmetrically and connected to the supply in Vparallel to eachother and with the condenser in series, whereby the polarity of thecondenser is adapted to be reversed by adjusting the heating current.

3.`A current rectifier according to claim 1, wherein one of the valvesis connected to the supply in series with the condenser. b5 In testimonythat I claim the foregoing as my invention, I have signed my name.

SIEGMUD sTRAUss.

